Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030230AbWBMWyP (ORCPT ); Mon, 13 Feb 2006 17:54:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030232AbWBMWyO (ORCPT ); Mon, 13 Feb 2006 17:54:14 -0500 Received: from gold.veritas.com ([143.127.12.110]:6444 "EHLO gold.veritas.com") by vger.kernel.org with ESMTP id S1030230AbWBMWyO (ORCPT ); Mon, 13 Feb 2006 17:54:14 -0500 Date: Mon, 13 Feb 2006 22:54:57 +0000 (GMT) From: Hugh Dickins X-X-Sender: hugh@goblin.wat.veritas.com To: "Michael S. Tsirkin" cc: Linus Torvalds , William Irwin , Roland Dreier , Nick Piggin , Gleb Natapov , Benjamin Herrenschmidt , Linux Kernel Mailing List , openib-general@openib.org, Petr Vandrovec , Badari Pulavarty Subject: Re: [openib-general] Re: madvise MADV_DONTFORK/MADV_DOFORK In-Reply-To: <20060213220947.GD13603@mellanox.co.il> Message-ID: References: <20060213154114.GO32041@mellanox.co.il> <20060213210906.GC13603@mellanox.co.il> <20060213220947.GD13603@mellanox.co.il> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-OriginalArrivalTime: 13 Feb 2006 22:54:12.0895 (UTC) FILETIME=[686DD2F0:01C630F0] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1109 Lines: 25 On Tue, 14 Feb 2006, Michael S. Tsirkin wrote: > Quoting r. Hugh Dickins : > > > Comments much better, thanks. I didn't get your point about mlock'd > > memory, but I'm content to believe you're thinking of an issue that > > hasn't occurred to me. > > I'm referring to the follwing, from man mlock(2): > > "Cryptographic security software often handles critical bytes like passwords > or secret keys as data structures. As a result of paging, these secrets could > be transfered onto a persistent swap store medium, where they might be > accessible to the enemy long after the security software has erased the > secrets in RAM and terminated." Ah, I get it, thanks: once parent and child have distinct pages, the child's is not locked in memory and might go out to swap. Yes, a valid point, and a relevant use for MADV_DONTFORK. Hugh - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/